Current theorizing about the Type A coronary-prone behavior pattern has linked the greater frequency of coronary heart disease among Type A individuals to the observation that Type A's seem to experience more stress in their everyday lives than Type B's. It is believed that chronic stress, much of which is induced by the overt behavioral characteristics of the Type A individual (overcommittment to work, self-imposed deadlines, etc.), results in physiological and endocrinologic changes which may eventually promote the probability of contracting coronary heart disease. The broad objectives of the proposed research are to pinpoint and delineate the kinds of environmental events which provoke a subjective and physiological state of stress in Type A individuals. More specifically, this research aims to investigate whether the experience of failure in an interpersonal competition situation has a differential effect on Type A and Type B individuals. This will be studied by providing subjects with bogus failure feedback during a reaction-time task and monitoring their physiological, affective, and performance responses during this experience. No published research to date has addressed the role of failure as a stressor in the Type A coronary-prone behavior pattern. The unique aspects of the proposed study are that not only will it explore the effects of failure, a previously unstudied stressor in this area, but also it will directly measure cardiovascular indices of arousal (pulse rate, finger pulse volume and blood pressure) in response to stress. Studying such physiological responses is consistent with testing the adequacy of the psychophysiological model of the Type A behavior pattern outlined above. The results of the proposed research will provide a better understanding of those environmental factors, such as interpersonal competition and failure, that elicit more intense stress reactions in Type A individuals than in Type B individuals.